ALAMEDA — A lane of Park Street closed Wednesday as crews worked to repair a sink hole up to 9 feet deep was reopened about 1 a.m. today. But crews still must return to the neighborhood to install permanent asphalt over the repairs, according to the Public Works Department.

A crew discovered the sink hole about 10 a.m. Wednesday while working on a damaged sewer line that had caused a dip in the road at Park Street near Webb Avenue, public works Director Matt Naclerio said.

“When we opened it to investigate, we discovered a huge void,” Naclerio said. “It was estimated to be from 6 feet to 9 feet deep.”

The discovery of the sink hole led crews to block the northbound lane of Park Street from Santa Clara to Lincoln avenues, causing a traffic back-up for motorists leaving the Island via the Park Street Bridge.

Naclerio said the road dip stemmed from a damaged lateral sewer pipe, which connects to the main line.

“The sink hole was so deep that we could not even find the lateral,” he said.

Naclerio said the incident marked just the second occasion that he has experienced a sink hole of such size during his 12 years as the city’s public works director.